Fixup example config.json file used by tests

Change-Id: Iacdb2313453ca630673c1de88c98c48f5af28555
Reviewed-on: http://review.couchbase.org/23924
Reviewed-by: Matt Ingenthron <matt@couchbase.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>